Grundig 40VLE630BH, Service Manual

Page: 45 / 180

TP CHASSIS / TELEVISION
45 September 2011
On S605 connector, 3 main control signals are sent to the power supply. The first
signal is “POWER_SW”; it is sent to the power source from 8th pin of S605 connector.
It switches on 12V and 24V voltages in the "ON" status. The second signal is
“BL_CTRL”; it switches panel's backlights on or off. This signal is sent from the 5
th
pin
of S605 connector to the power supply and from there, to panel inverter. In cases
where 5
th
pin is high (3.3V), backlights are switched on. The third signal is “BRI_ADJ”.
It is sent from the 6th pin of S605 connector to supply unit, and from there to panel
inverter. BRI_ADJ signal represents DIMMING in our previous chassis; it determines
the brightness level of backlight depending on the value set in the user menu. When
BRI_ADJ is high (3.3V) maximum brightness level is reached. This signal can be a
square wave or a DC value according to the panels using PWM dimming and DC
dimming.
In Stand-By mode, only +5V2_ST and VCC3V3-ST voltages exist on chassis.
+5V2_ST is used by LED and IC605 with VCC3V3-ST output. VCC3V3-ST voltage is
used in main IC and SPI Flash supplies. In Stand-By mode, integrated circuits and
regulators remain off as long as possible to ensure lower power consumption. In TP-
chassis products, Stand-By power consumption is 0.5W.
“POWER_SW” signal sent from the main IC makes the device exit Stand-By mode.
With POWER_SW signal; 12V and 24V voltages of PSU are turned on; firstly IC608
VCC1V05 IC starts to give output on the chassis and makes POWER GOOD (PG)
signal step in to start other regulators’ operation. With PG signal, PG1 is created; and
with PG1 signal PG2 is created; with step down converters, linear regulators are
switched on in sequence. PG1 enables signal switches on the step down regulators
VCC1V25 (IC604) and VCC1V5 (IC600), respectively. Then, with PG2 signal; the
voltages of VCC3V3(601), VCC2V5(IC602), VCC3V3_ETH(IC308) and VCC3V3_S2
(IC307) are created.
From VCC12V signal, VCC5V3_FE is created and from there, VCC5V voltage is
created. +5V_USB supply is created from VCC12V.
12V PANEL-VCC voltage is controlled by means of switching T604 with TCON_ON
signal sent by main integrated circuit.
VCC1V5 voltage provides supply for DDR3 RAMs (including Ursa RAM) and main IC;
VCC2V5 voltage for main IC, DVB-T2 demodulator; VCC1V05 voltage for main IC
and DVB-S2 demodulator; VCC1V25 voltage for DVB-T2 demodulator and 100Hz
URSA processor, VCC3V3 voltage for EEPROMs, main IC, NAND flash, DVB-T2
demodulator, DVB-S2 demodulator, I2C pull-ups and RESET integrated circuit.
24V VCC_AUDIO voltage provides supply for audio and subwoofer amplifier.
VCC5V voltage supplies tuner, HDMIs, VGA, USB and DVB-S2 demodulator.